Electric gaseous discharge device



May 26, 1936. U 2,042,140

ELECTRIC- GASEOUS DISCHARGE DEVICE Filed Aug. 17, 1954 &' .1

INVENTOR 7v 6.27 I ATTZRNEY Patented May 26, 1936 Albert Biinger,Berlin-Pankow,

Germany, as-

signor to General Electric Company, a corporation of New YorkApplication August 17, 1934, Serial No. 740,304 In Germany September 7,1933 4 Claims.

The present invention relates to electric gaseous discharge devicesgenerally, and more particularly to discharge devices of the type whichare operated with a relatively constricted arc.

5 The particular object of the invention is to provide a novel methodand means for controlling the arc path within a discharge device inorder to prevent the are from impinging on the envelope wall. A furtherobject of my invention is to utilize the usual arc stabilizing impedanceto produce this new result. Still other objects and advantages of myinvention will appear from the following detailed specification, or froman inspection of the accompanying drawing.

The invention consists in the novel steps of the method and in theunique combination of ele- .ments which is hereafter set forth andclaimed.

In operating gaseous electric discharge devices, such as a high pressuremercury vapor lamp with a constricted arc discharge, difficulties areencountered whenever an attempt is made to operate the device with theare extending in. other than a vertical line. These difliculties arecaused by the fact that the arc tends to rise, due to the heating of thegas in the arc stream, and thus curves toward and impinges upon theupper wall of theme tube as the latter is moved toward a horizontalposition. The glass which is commonly used for these are tubes is notadapted to withstand the ensuing severe localized heating and hencesoftens, allowing the tube to lose its shape and at the same timeevolving copious amounts of gas into the discharge path, either of theseeffects alone being enough to ruin the discharge 85 device.

I have now discovered that this difllculty is entirely overcome by amagnetic force of a magnitude which just neutralizes the upward forcewhich is exerted upon the arc stream. as a result of the unequaltemperatures within the lamp, the arc thereupon continuing to pass downthe center of the arc tube regardless of the position of the latter. Asa result a serious limitation on the utilization of these dischargedevices, particularly as light sources, is now eliminated without anychange in the arc tube itself. Since it is essential, for best results,that this magnetic force should be proportional to the current and inphase therewith I have found it to be desirable to use 'one or moreinductances connected in series with the arc to produce this magneticfield. These inductances serve to stabilize the arc and thus replace, inwhole or in part, the stabilizing im- 55 pedance which is ordinarilyused with this type ducing lines of force whose direction is indicatedof device when it is operated on a constant potential circuit.

For the purpose of illustrating my invention I have illustrated twoembodiments thereof in the accompanying drawing, in which 5 Fig. 1 is aschematic diagram of an electric gaseous discharge lighting tube,together with a group of series inductances, and

Fig. 2 shows a schematic diagram of a modifiv cation of the structure ofFig. 1. 10

As shown in this drawing, with particular reference to Fig. 1, thedischarge device has an elongated tubular envelope 1 of glass or thelike which contains any suitable gas or vapor, or mixture thereof. Forexample, a filling of argon 15 at a pressure of the order of 5 mm. ofmercury, together with enough mercury to produce a pressure of the orderof an atmosphere when it is all vaporized, has been found to giveexceptionally good results. A pair of electrodes 2 and 2 are 20supported by the inleads, 3 and 3, respectively, which are sealed intoopposite ends of said envelope. These electrodes, which are of anydesired type, .are only conventionally illustrated, since the structurethereof forms no part of my invention. It may be remarked in passing,however, that these electrodes are preferably thermionic, with thenecessary heating provided by the discharge itself, or in some cases, byauxiliary heating means. Various well known means 30 of facilitating theinitiation of the discharge, such as auxiliary electrodes or conductingstrips on the surface, may also be employed where de-- sired, but sincethey form no part of the present invention they will not be described indetail. The inlead 3' is connected directly to the terminal 4 of asuitable source of alternating current of customary frequency, while theinlead 3 is connected through a series of inductances 5, 6, I, 8 and 9to the other terminal 4 of said source. The 40 inductances 6, 1, 8 and9, which are preferably iron cored are arranged more or less uniformlyover the midsection of the tube l, with their axes substantiallyhorizontal and normal to the axis of said tube. The inductance 5 isomitted in some cases, where the other inductances are of suflicientsize to stabilize the arc.

In the use and operation of this lamp the arc current flows through theinductances 5, I, 8 and 9, and thus produces a magnetic field about eachthereof, the lines of force of which at a given moment are indicated bythe dotted lines 6', I, 8 and 9'. At the same instant the arc currentflowing between the electrodes 2 and 2 is proby dotted lines Ill, ll, l2and I3. Since the inductances 6, I, 8 and 9 are so wound that the linesof force of both said inductances and the are current are in the samedirection above the arc itself, there is a repulsive force exerted uponthe arc stream. As a result of this force the arc is forced downwardlyto the path indicated by the long-dashed line I4, instead of permittingit to take the path which is indicated by the dot and dash line l5 whichit would normally follow in the absence of the inductances 6, I, 8 and9. The regulation of this magnetic force in order to obtain thisstraight line discharge along the center of the tube is very simple,since the strength of this force depends both upon the distance betweenthe inductances and the arc and upon the relative direction of the linesof force. Hence the arc can be brought into the desired position in thetube l either by adjusting the gap between the difierent inductancesand'the tube, or by changing the angle which they form with thedischarge path. Furthermore the number of turns on the differentinductances may be made different, it being noted that'a relativelygreater magnetic force is needed in the vicinity of the electrodes thanis required in themiddle of the arc.

In case it is desired to arrange the inductances below the arc tube I itis necessary to reverse the direction thereof, as shown in Fig. 2, sothat the lines of force 6', I, 8' and 9' are in the opposite directionto the lines of force I0, I I, I2 and I 3 below the arc path. With thisarrangement the arc is pulled rather than forced downwardly and followsthe path it as in Fig. 1.

While I have illustrated my invention by reference to certainembodiments thereof it is to be understood that various omissions,substitutions and changes may be made therein, within the scope of theappended claims, without departing from the spirit thereof, it beingobvious, for example, that the exact number of inductances employed toinfluence the path of the are is immaterial, and may be as small as one.and that these inductances may also be in part above and in part below,if desired, instead of all in a single position, as shown.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:-

-1. An electric gaseous discharge device comprising a sealed envelopecontaining a gaseous atmosphere and having electrodes sealed therein,said envelope being mounted with the electrodes in such relation that aline between said elec-v trodes is at an angle to the vertical, wherebyvforces are produced during operation tending to move the arc stream awayfrom said line, in combination with means to produce a magnetic fieldwithin said envelope in such a direction and of such an intensity thatthe magnetic reaction thereof with the normal arc current equals theforces tending to move the arc stream out of a straight path within saiddevice.

2. An electric gaseous discharge device comprising a sealed envelopecontaining a gaseous atmosphere and having electrodes sealed therein,said envelope being mounted with the electrodes in such relation that aline between said electrodes is at an angle to the vertical, wherebyforces are produced during operation tending to move the arc stream awayfrom said line, in combination with means to produce a magnetic fieldwithin said envelope in such a direction and of such an intensity thatthe magnetic reaction thereof with the normal arc current equals theforces tending to move the arc stream out of a straight path within saiddevice, said means comprising an inductance connected in series withsaid device.

3. An electric gaseous discharge device comprising a sealed envelopecontaining a gaseous atmosphere and having electrodes sealed therein,said envelope being mounted with the electrodes in such relation that aline between said electrodes is at an angle to the vertical, wherebyforces are produced during operation tending to move the arc stream awayfrom said line, in combination with a plurality of inductances connectedin series with said device, the relative position of said inductanceswith respect to said device being adjusted so that the magnetic reactionbetween the field produced thereby and the normal are current equals theforces tending to move the arc stream out of a straight path within saidenvelope.

4. The method of maintaining a constricted arc discharge which isinclined to the vertical in a gaseous atmosphere out of contact with thewall of a vitreous envelope which comprises producing within saidenvelope a magnetic field whose intensity and direction is such that themagnetic reaction with the normal arc current equals the forces tendingto move said are into contact with said wall which result from theinclination of said are ALBERT BfiNGER.

